Microsoft's new Windows
7 operating system launched to great fanfare last week, but one
of the most important features for Solid State Drive owners has been
commonly overlooked. That feature is the the Trim attribute of the
ATA Data Set Management Command, commonly known simply as TRIM.

SSDs
are like traditional
magnetic storage based hard drives in that data still resides on
the drive after it has been deleted by the OS. That data block is
overwritten by new data when the amount of fresh unused storage is
depleted. On most SSDs, data is erased in 512KB blocks even though
data is written in 4KB pages. This means that if a single 4KB page
needs to be updated, the whole block must be erased and rewritten,
slowing down the drive significantly. This is particularly true for
random write operations.

TRIM synchronizes the operating
system's view of deleted files with those that are deleted, but not
yet erased on the hard drive. SSD controllers are good at managing
data, but they have no optimization for different file systems. TRIM
lets the controller know that data has been deleted so that it can
wipe the entire block when it is not busy with other operations. This
significantly speeds up write operations, especially when the drive
is nearly full.

Intel's second
generation X25-M series SSDs have been selling very well, and the
company has been promising TRIM support to its many customers. It is
releasing new firmware to the public that will enable the use of
TRIM, but only with its latest generation of mainstream SSDs using
34nm
NAND flash.

"Fast and reliable access to data is
critical for our SSD users," said Pete Hazen, Director of
Marketing for Intel's NAND Solutions Group. "The latest firmware
and toolbox upgrade for Intel 34nm SSD users provide a host of new
management, information and diagnostic tools to help SSDs retain
out-of-box performance. We are encouraging our 34nm customers to
download the new firmware update today. Not only will Windows 7 users
receive the performance enhancements of the Trim command, but so will
our Windows XP and Vista
users."

Owners of second
generation 160GB X25-M drives running Windows 7 will also see a 40
percent performance boost to sequential write speeds. The firmware
update allows the drives to write data at up to 100MB per
second.

Backing up data before the firmware update is highly
recommended, but existing data on the SSD will not be erased. Intel
also cautions against using the firmware utility over RAID, as each
drive must be flashed individually. The firmware update is available
here.

TRIM has been implemented in Linux 2.6.28 since
December of last year. All older solid state drives will need
firmware updates to enable TRIM support, otherwise the new command
will be ignored by the controller.

"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -- Isaac Asimov